Hey, news like this makes those poor 'late hatchers' feel like those poor pregnant women past their due date (which is most of them) when they hear about the "lucky duck" who has their baby ten days early.
That sounds about right to me. I run my temps about half a degree above the recommendation, and it turns out early hatches with vigorous ducklings for me about a day early pretty consistently.
Also, I usually get a pip about two days before the actual hatch, so a pip today will probably be a duckling Saturday so if the rest pip tomorrow... you'll still have most of your babies on Sunday.
This is my first hatch from my own pekin eggs too and only 2 out of 6 made it to the CHICKEN lockdown. HAHAHAHA! 7 of the chicks hatched and I didn't expect the ducks til at least Sunday morning, as day 28 is 7 pm Sunday.